Gas sorption studies on a highly-thermostable microporous Zn(II) coordination polymer constructed from 2D honeycomb layers

• A highly-thermostable microporous Zn(II) coordination polymer
• High CO2 capacity and CO2/N2 selectivity
• Understanding the sorption behavior at molecular level by GCMC simulation

By combining experiment with molecular simulation, the CO2 sorption performance of a 2D honeycomb layered coordination polymer, {[Zn2(bpydb)2(H2O)2](DMA)3(H2O)}n (1) (bpydb = 4,4′-(4,4′-bipyridine-2,6-diyl) dibenzoate) was systematically investigated. The desolvated 1 not only shows high CO2 capacity (72.5 cm3/g at 273 K and 42.9 cm3/g at 298 K) with a moderate high zero-coverage adsorption enthalpy (29.7 kJ/mol), but also exhibits excellent CO2/N2 selectivity around room temperature. To better understand the adsorption behaviors and adsorption sites for CO2 in 1, GCMC simulations were carried out, which indicate that the open metal sites between two adjacent layers account for the high CO2 sorption capacity and strong CO2 binding ability. Moreover, the thermal stability of 1 was further confirmed by the TGA and VT-PXRD, which indicate that 1 could be thermally stable up to 400 °C.

The gas sorption behaviors of a Zn(II) 2D layered coordination polymer was investigated both experimentally and theoretically. The relevant results show that the coordination polymer possesses high CO2 sorption ability and CO2/N2 separation performance, which, from the GCMC simulation results, should be attributed to the open metal sites along with the suitable pore surroundings contribute.Figure optionsDownload as PowerPoint slide